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WARWICK MANUFACTURING GROUP Product Excellence using Six
Sigma
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P R O D U C T E X C E L L E N C E U S I N G S I X S I G M A
Quality Function Deployment
Warwick Manufacturing Group School of Engineering
University of Warwick, Coventry, CV4 7AL, UK Phone +44 (0)24
7652 4240 Fax +44 (0)24 7652 4307
e-mail [email protected]
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Q U A L I T Y F U N C T I O N D E P L O Y M E N T
Table of Contents Introduction 1
What is
QFD?......................................................................1
Scope of
QFD......................................................................1
Who Uses
QFD?..................................................................2
The Purpose of
QFD...........................................................2 The
System..........................................................................2
The Customer Requirements 6 The Customer
Chain...........................................................6
Example
......................................................................................................................
6 WARNING: Internal Customers
........................................7 Example
......................................................................................................................
7 What is Meant by Customer?
............................................7 Obtaining Customer
Requirements....................................7 Postal
Questionnaires
...............................................................................................
8 Telephone Interviews
...............................................................................................
8 Face-to-face Interviews
............................................................................................
9 Clinics
..........................................................................................................................
9 Focus
Groups.............................................................................................................
9
Listening......................................................................................................................
9
Technical And Regulatory Requirements 12 Organising Customer
Requirements 12
The Process of
Organisation............................................. 13
Entering the Customer Requirements onto the QFD
Chart........................... 16
Establishing Customer Importance Ratings & Customer
Competitive Comparisons 19
Example Questionnaire
.................................................... 19 Entering on
the QFD chart............................................... 21
Customer Complaint History 25 Establishing Priorities 27
Establish Engineering Characteristics 30 Technical Competitive
Comparisons 35
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Aircraft Seat Study
.............................................................35
Other Sources of Data
.......................................................38
Establishing Links 41 Relationships Matrix
.........................................................41
Conflicts
Matrix.................................................................43
Establishing technical targets and ratings 47 Engineering
Targets .........................................................47
Degree of Technical
Difficulty..........................................50
Engineering Characteristic Importance Rating 52 Analysing The
QFD Chart 55 Next Steps 61
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Table of Figures Figure 1. The QFD chart.
...................................................................................................................4
Figure 2. Gathering and organizing customer
requirements..........................................................5
Figure 3. Technical & regulatory
requirements..............................................................................11
Figure 4. Aircraft seat example of organizing customer
requirements. ......................................15 Figure 5.
Aircraft seat customer requirements continued.
...........................................................16
Figure 6. Customer and technical & regulatory requirements.
....................................................17 Figure 7.
Customer importance ratings and competitive comparisons.
.....................................18 Figure 8. Example
questionnaire......................................................................................................20
Figure 9. Distribution of importance points.
.................................................................................22
Figure 10. Customer importanca ratings and
comparisons..........................................................23
Figure 11. Customer complaint
history...........................................................................................24
Figure 12. Customer complaint
history...........................................................................................26
Figure 13. Customer priorities.
.........................................................................................................28
Figure 14. Engineering characteristics.
............................................................................................29
Figure 15. Engineering characteristics - aircraft seat example.
....................................................33 Figure 16.
Technical competitive
comparisons..............................................................................34
Figure 17. Technical competitive comparisons - aircraft seat
example. .....................................37 Figure 18. Other
sources of technical data.
....................................................................................39
Figure 19. Establishing links.
............................................................................................................40
Figure 20. Establishing links relationship matrix.
..........................................................................42
Figure 21. Establishing links - correlation matrix
..........................................................................44
Figure 22. Technical targets and
ratings..........................................................................................46
Figure 23. Establishing engineering targets.
...................................................................................49
Figure 24. Establishing degree of technical difficulty.
..................................................................51
Figure 25. Engineering characteristics importance ratings.
..........................................................53 Figure
26. Analysing the QFD chart.
..............................................................................................54
Figure 27. Analysing the chart for strong relationships.
...............................................................57
Figure 28. Analysing the chart for whene we hold the lead.
........................................................58 Figure
29. Analysing the chart for where we can gain competitive
advantage..........................59 Figure 30. Analysing the
chart for where we lag and must
improve...........................................60
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Q U A L I T Y F U N C T I O N D E P L O Y M E N T
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Introduction What is QFD? QFD is a system for designing a
product or service based on customer demands that involves all
members of the producer or supplier organisation. In Japanese,
deployment refers to an extension or broadening of activities and
hence Quality Function Deployment means the responsibilities for
producing a quality item must be assigned to all parts of a
corporation. It is sometimes referred to as the most advanced form
of Total Quality Control, Japanese style. The system can be
understood by defining each of the terms in Quality Function
Deployment within the context of QFD.
Quality - Meeting Customer Requirements Function - What Must Be
Done - Focusing the attention Deployment - Who Will Do It, When
Scope of QFD QFD theory started in 1972 at Mitsubishis Kobe
Shipyard when they began using a matrix that put customer demands
on the vertical axis and the methods by which they would be met on
the horizontal axis. This was recognised almost immediately as a
major breakthrough. Since that time the Japanese have developed the
system to encompass other areas of a secondary nature such as
improved communications between the design and manufacturing
departments, considering the function of the product, potential
failure modes, possible new technologies and cost reduction. This
course however, will consider in the main a primary level QFD
study, but will refer to the secondary and continuing levels in the
final sections.
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Who Uses QFD? Current Japanese users of QFD concepts include
Nissan, Toyota, Komatsu, Nippondenso and Honda. In the United
States of America users include Ford, GM, Chrysler, DEC, TI, 3M,
HP, AT&T Bell Labs, NovAtel, Xerox, Exxon and Dow.
The Purpose of QFD The purpose of QFD is three fold. Firstly, it
allows us to get higher quality products to market faster and at a
lower cost. Secondly, we will achieve customer driven product
design and, finally, it will provide a tracking system for future
design or process improvements.
The results we can expect by carrying out the QFD studies are
many:
Better understanding of customer needs Improved organisation on
development projects Improved introduction to production Fewer
design changes late in development Fewer manufacturing start-up
problems Reputation for being serious about quality Increased
business Documented product definition based on customer
requirements
The System QFD achieves these results by breaking down customer
requirements into segments and identifing means for achieving each
segment. QFD also involves all parts of a company and facilitates
simultaneous product and process design. Finally, it integrates the
use of other quality tools such as Taguchi Methods.
The QFD process is as follows:
Customer Requirements
Design Requirements
Component Characteristics
Operations Requirements
Working Procedures
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This process begins with the first level QFD chart, a schematic
of which is shown overleaf. The following sections of these course
notes will now unfold the process of gathering information,
entering it on the chart and analysing it.
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Figure 1. The QFD chart.
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Figure 2. Gathering and organizing customer requirements.
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The Customer Requirements In order for any company to stay in
business they must sell their products/services and be able to rely
on repeat business. This can only be done with a backbone of
continual satisfaction on behalf of the customer. In turn, customer
satisfaction can only be achieved if we can fulfill the customers
requirements. Hence, the gathering and use of customer requirements
is the foundation of QFD.
It follows, therefore, that the first area that must be
understood in QFD is that of customer requirements. As QFD is a
technique for translating the customer requirements into a product
design, we must be able to gather these requirements. It is
essential, however, that the requirements we gather are the true
customer requirements. We as engineers and managers are so close to
our product that our level of expectation and our values are far
removed from the average customer. Hence, we cannot speak for
todays customers.
In order to understand the area of customer requirements we must
understand three distinct factors:
The Customer Chain What do we mean by Customer in QFD Obtaining
Customer Requirements
The Customer Chain It is necessary in order to obtain as full a
picture as possible that we understand who our customer actually
is. For some businesses we may only have one or two types of
customer, but for the majority of todays businesses there will be a
chain of customers. This raises the question, what do we mean by a
customer chain? By customer chain we mean that for a simple product
there could be more than one customer. For a simple product the
chain may be short i.e. an owner, an operator and a user. The
examples below show simple chains but it is conceivable that they
could become much longer and more complex.
Example Manufacturers Product Customer
Breakfast Cereal Supermarket - Parent who buys - Child who
eats
Aircraft Seat Aircraft Manufacturer - Aircraft lease company -
Airline - Passenger
If a company has a very complex customer chain it is possible to
use a system for its identification similar to that used for
supplier chain analysis. The system for customer chain analysis
involves simply identifying who is the companys
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immediate customer and who is the end user. Thus, by asking
questions of each it is possible to fill in the customer chain
between them.
WARNING: Internal Customers There is one type of customer which
when considering QFD we must be very careful of, namely, the
internal customer. The reason for this comes from why customer
requirements are so important. By satisfying them we stay in
business because people buy our products/services. As such it must
always be the external customers we satisfy as it is they who pay
for our products/services. Therefore, if we include internal
customers requirements which then lead to a compromise on an
external customer requirement, we have not satisfied the external
customer. The correct answer would be to satisfy the external
customer and then solve the associated internal problems. In other
words, we become customer driven.
Example The designers at a small boatyard are designing fishing
boats. The owner, the external customer, has asked for an aluminium
wheelhouse. Production, the internal customer, are saying they want
anything but aluminium in the vessel because they cannot work
aluminium. The designers compromise and specify a wooden
wheelhouse. The result is that the external customer is not
satisfied. What the designers should have done was to specify the
aluminium wheelhouse then considered the associated internal
problem. This will automatically happen in QFD if the external
customers only are considered as the internal problems will be
highlighted and then dealt with at a later stage.
What is Meant by Customer? In QFD, when we refer to the customer
in terms of gathering their requirements, it is not sufficient just
to consider our customer chain. We must consider the individual
parts of that chain in more detail. It is not sufficient, if we
want a full picture, just to consider those people who bought our
product; we must look further.
We should consider the following people:
Those who bought our products Those who bought competitors
products Those who switched to our competitor Those who are
satisfied Those who are not satisfied
Obtaining Customer Requirements In the domain of market research
there are two types of data, namely, primary and secondary. For the
purposes of QFD we consider in the main primary data techniques.
The main reason for this is as follows:
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Secondary data is that which is not directly gathered from field
work.
Examples of secondary data are:
Government produced statistics Company accounts Commercially
produced reports Business news in newspapers and trade
magazines
Although this type of data can be useful to parts of QFD, for
customer requirements it is necessary that the requirements are
gathered in the customers own language. That is to say that the
words used in the recording of the requirements should be the
actual words used by the customer. The techniques used to get this
type of information are generally referred to as Field Research
Techniques and they produce what is called primary data.
Field research techniques can be broken down into those using
questionnaires and those using non-questionnaire techniques.
Questionnaire techniques involve the use of a set of questions
which respondents are asked to answer. The type of questions asked
can be very formal and structured, requiring a simple yes, no or
dont know response or they can be semi-structured, requiring an
explanation of a customers action.
Before listing the questionnaire techniques, there must be one
word of warning about using them in the context of QFD. As the use
of them is to produce the customers requirements, both technical
and emotional, we must be careful not to structure the
questionnaires in such a way that they lead the customer into a
particular response or in fact, miss an area of requirement
completely.
Questionnaire methods consist of three basic types:
Postal Questionnaires Postal Questionnaires are impersonal. The
respondent is left to fill in a questionnaire alone. It is the most
structured of the questionnaire techniques, and its main advantage
is its comparative low cost - an interviewer is not required to put
the questions directly to a respondent - hence, it is possible to
send the questionnaire to a large number of potential respondents.
However, the respondent is under no obligation or pressure to
answer, so may simply throw away the questionnaire or leave it a
long time before replying. As a result, response rates are
generally low and replies may take a long time to come in. As a
result, respondents may not represent a true cross section of the
population.
Telephone Interviews Telephone interviewing, because it involves
an interviewer putting questions to respondents, often has the
advantage of drawing out answers which are given
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instantly. It is more expensive than a postal survey because a
trained interviewer must be employed and telephone calls can be
costly.
Face-to-face Interviews Respondents meet an interviewer face to
face. As a result, the procedure can be more informal than the
other two techniques, with time to elaborate on the meaning of
questions and the reasons that the answers were given. This is,
however, a very costly method in time and money.
For non-questionnaire techniques there are three basic
categories:
Discussion techniques Diary panels Audit techniques
For QFD, because we are considering products at the design stage
we are interested in only one of these above categories. The
category of interest is the discussion technique. Of this type
there are various different methods.
Clinics The clinic method is very useful for the purposes of QFD
as it provides a variety of feedback information. A clinic takes
the form of grouping customers at a venue where they may see the
product in question, or a mock up, and its competition. The group
will encompass all the types of people referred to previously,
those who bought your products and those who did not. The feedback
that these people give can thus be noted throughout the period of
the clinic.
Much use of clinics has been made by the car manufacturers. They
use clinics to expand on the information gathered from postal
surveys. Selected respondents are asked to bring their cars to a
venue where the manufacturer will also have examples of the
competition. The customers can then discuss their likes and
dislikes and compare the competition.
Focus Groups Focus Groups are small groups of about eight to
twelve people. These groups should be a cross section of the
population selected at random who agree to come to a venue for a
one or two hour discussion. These discussions should be led by
someone experienced at such things who is capable of moving the
discussion in the right direction so that all issues are
covered.
There is one other method for acquiring customer information
which is not covered in the above field techniques. This final
technique is one that the Japanese have shown that they are
exceptionally good at: it is called Listening.
Listening Listening takes the form of engineers and managers
simply listening at trade shows and outside retail outlets. What
they must listen for is simply the comments of
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customers, potential customers and past customers about the
particular product in which they are interested.
The example below shows the customer requirements as gathered
from the customer chain for the aircraft seat example:
Passenger
Comfortable, does not give you bum ache. Enough leg room. Lumbar
support does not hurt short person. Does not burn. Hole in tray for
coffee cup. Comfortable seat belt. Seat belt feels safe. Magazines
can be easily removed from rack. Comfortable when you recline. Does
not hit person behind when you recline. Back can be adjusted to any
position and does not slip. Not dirty. Nice colour. Does not soak
up a spilt drink. Does not make you sweat. Arm rests not too
narrow. Arm rest folds right away.
Airline
Easy/cheap to refit. Easy to clean. Easy to move around. Fit
more passengers in. Passengers feel comfortable. Fabric in certain
colours. Fabric stain resistant. Meets regulatory requirements.
Long life. Low operating cost. Cheap to service.
Aircraft Manufacturer
Cheap. Light weight. Durable. Easy to fit in plane. Safe in
crash. Meets regulatory requirements.
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Figure 3. Technical & regulatory requirements.
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Technical And Regulatory Requirements There are some
requirements which the customers will not identify. These
requirements will be either technical or regulatory requirements.
Regulatory requirements are such things as government legislation,
safety requirements, quality standard requirements, classification
requirements etc. Technical requirements occur because the company
may have some specific plans for the new product. For example,
complete automated assembly, single monocoque construction etc. All
these types of requirements should be included in the requirement
side of the chart so that total satisfaction can occur i.e.
customer, company, regulatory.
Earlier, it was mentioned that we had to be careful of internal
customers. The technical and regulatory section of the chart is the
only place in which they should appear.The technical and regulatory
requirements are added at the bottom of the chart as will be shown
later.
In the case of the aircraft seat example, the technical and
regulatory requirements are as follows:
FST 1000 - fire safety standard
16G load case - safety standard
Max allowable deflection interface to floor rails
Organising Customer Requirements There are three reasons behind
organising the customer requirements:
To organise the raw customer data into groups of associated data
to simplify using the QFD charts at a later stage.
Because the customer requirements are listed in the language of
the customer, the process of organising the data allows the QFD
team to reach a common understanding of customer wants.
The customer research techniques by the nature of their sampling
and the customer responses may not highlight all the customer
needs. The process of organising listed below gives the team the
chance to surface areas and requirements which the customer has not
talked about.
In organising the customer requirements there are three
categories into which they can be put. These are:
Primary: Are the very basic customer wants. At this level all
the requirements should give an overall product view. For example,
Toyota has only four primary categories for
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describing a new car: Good at first glance, easy ride and
handling of car, feels safe when driving, long life.
Secondary: These requirements are the primary level in more
detail and are in fact the headings for groups of tertiary level
requirements
Tertiary : These are the requirements in their most detailed
level.
In fact, when developing these organisation levels with the
customer requirements we start at the tertiary level and work
outwards towards the primary level. The reason for this is that QFD
should always be customer driven and, therefore, we should start
with the information the customer has given us. If the customer is
a manufacturer of industrial goods, that manufacturer can generally
identify its own primary requirements.The buying public, however,
often mentions secondary or tertiary requirements when asked what
it wants.
The Process of Organisation Step 1: All the customer
requirements should be written on to pieces of card, or post it
notes. Each piece of card should contain only one of the
requirements.
Step 2: The cards should now be pinned to a board or spread out
on a large table where all members of the team can see them
easily.
Step 3: The team should now start to group cards together that
have some relationship. It will be the discussions during this step
which lead to reaching a common understanding of customer wants. It
is quite possible that certain requirements appear to belong to
more than one group. If this is the case, at this stage, repeat
cards should be written and put with all possible groups.
Step 4: Once the cards have been grouped the team should write
title cards which best describe the category for the cards. The
title cards should be as specific as possible. Occasionally there
will be cards within the group which could easily act as title
cards for the group. If this is the case it should become a title
card. Once this has been done the cards have effectively been
grouped into secondary (title) and tertiary (group)
requirements.
At this stage the team should discuss any doubling up of cards
from the step and decide to which single group they should belong.
At the end of the organising process there should be no repeated
requirements.
It is possible that confusion will arise as to whether a
requirement should be a secondary requirement or tertiary
requirement. The team can alleviate this problem by applying a
simple test.
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Test: The Why Question
Of the requirement the team is unclear about being secondary or
tertiary, ask the question, Why does the customer want this? An
experienced team should be able to answer this question. If the
answer is simply the original requirement restated in a different
format, then the requirement is tertiary. If on the other hand, the
answer is more detail about the requirement then the requirement is
secondary.
Step 5: Once the secondary requirements have been found, the
team should discuss each one in turn to surface any possible
tertiary requirements which could also be included.
Step 6: Now steps 3, 4, and 5 should be repeated for the
secondary requirements in order to get primary requirements and
possible missing secondary requirements. If new secondary
requirements surface, these will have to be discussed to obtain the
underlying tertiary requirements. It may even be necessary to go
back to the customers to find their tertiary requirements for the
identified area.
Step 7: The primary, secondary and tertiary requirements can now
be drawn in a tree diagram. This is shown in the example below for
an aircraft seat.There is one word of warning for the QFD team when
they are discussing additional requirements. The team should take
care not to introduce engineering terminology. The team should
continually try to think like the customer at this stage.
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Figure 4. Aircraft seat example of organizing customer
requirements.
Note
On the above diagram and on the following sheets, the following
legend has been used with respect to the previously mentioned
customer chain:
P Passenger Requirement
A Airline Requirement
AM Aircraft Manufacturer Requirement
* QFD Team Developed Title
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Figure 5. Aircraft seat customer requirements continued.
Entering the Customer Requirements onto the QFD Chart Once all
the requirements have been gathered and organised, they can be
entered on the QFD chart on the left hand side as shown on the next
page.
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Figure 6. Customer and technical & regulatory
requirements.
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Figure 7. Customer importance ratings and competitive
comparisons.
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Establishing Customer Importance Ratings & Customer
Competitive Comparisons Although these are two distinct areas with
different objectives, they can be carried out together on the same
customer survey. Hence, they have been linked together in this
section. After the customer requirements have been gathered it is
necessary to quantify two separate issues:
How important each of the characteristics are to the customer.
It will definitely be the case that the customer will attach more
importance to certain requirements than others. It is important to
QFD that we are able to reflect these different importance
ratings.
How the customer rates how well our company performs on each of
his/her requirements against the best of our competition.
It is necessary to have both of the above pieces of information
so that the team can use them in the analysis of the QFD chart to
focus in on the sources available to the company for competitive
advantage.
Any of the survey techniques mentioned in the customer
requirement section can be used to gather customer importance
ratings and competitive comparisons. For many products, e.g. cars,
it is possible to obtain lists of owners from government registers
for both a companys products and its competitors. For those that
lists cannot be found the process becomes much harder.
The example below shows the type of survey sheet that could be
used for a postal survey.
Example Questionnaire The following page shows an example
questionnaire as used by a chain of Pizza Restaurants.
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Figure 8. Example questionnaire.
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If the above survey is used on both purchasers of your own
companys products and purchasers of competitors products, a picture
of how well you compete against your competitors can be built
up.
Because large surveys must be carried out it is necessary to
take an average of all the survey data. A simple method for doing
this is to average all the survey data for each item and double
that average, finally rounding it to a whole number. In doing this
if the survey data gave ratings from one to five the results we
have now will be more detailed giving ratings from one to ten.
NOTE:
The reason that we ask customers just to rate on scales from one
to five is that it is easier for the customer to choose. His choice
is limited to top, middle, bottom, above middle or below middle.
The process of averaging and rounding up then gives us the
increased distribution we require to make the QFD analysis
easier.
Having said this however, it is conceivable that the increased
distribution will still not give the difference in definition that
we require, i.e. we may still have very many items which are ranked
identically. If this is the case, then other survey techniques must
be used to build on the basic data already found. A focus group
could be used where the small group of people is asked to discuss
or debate the items concerned. The alternative is to use a clinic
technique. In this case the group of customers at the clinic would
be given a sheet, as shown overleaf, and asked to distribute 100
points between the secondary requirements. This forces the
participants to think about the relative importance of each of the
secondary items. Once the participating customers have completed
this they are asked to break down the points that they have
allocated to each of the secondary requirements to the appropriate
tertiary requirements. This method will thus give the increased
definition we require.
An example of the type of form used in the clinic is shown on
the next page.
The final possibility is in fact listening. A wealth of
competitive comparison information can be acquired by engineers and
managers listening and taking note of what customers say at
exhibitions, trade shows and retail outlets. Comments like I like
the boot but it isnt as big as the Toyota we looked at yesterday if
noted, can prove invaluable.
Entering on the QFD chart The above is shown entered on the QFD
chart for the aircraft seat example on the two pages following the
clinic example overleaf.
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SECONDARY Points TERTIARY Points
Comfortable upright Arm rest folds right away
Arm rest wide enough
Enough leg room
Doesnt give you bum ache
Doesnt hurt shoulders of taller person
Lumbar support doesnt hurt short person
Comfortable reclined Doesnt hit person behind when reclined
Back can be adjusted to any position and doesnt slip
Figure 9. Distribution of importance points.
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Figure 10. Customer importanca ratings and comparisons.
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Figure 11. Customer complaint history.
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Customer Complaint History There is one other area which adds to
the useful information we can gather for use in the QFD study. Most
businesses today have records of customer complaints. The reason
for complaint histories being useful to the QFD study is that often
the complaint history cannot be related to a specific customer
want. This is because when the service call report was written the
engineer will have translated the customers complaint language into
technical language and hence the related customer want is lost.
The identification of the customer complaints and their
inclusion in the QFD chart allows the QFD team to identify the
nature of the customer complaint and the time frame over which it
arises. For example, take a car door. The customer may want a door
which is easy to open and close. We as manufacturers have designed
the door such that this is the case. When we look at the complaint
history however, we find that there have been a great many
complaints in this area. On investigation the team finds that the
hinge design becomes very stiff after certain conditions combined
with a certain amount of wear.
The chart on the next page shows how complaint history should be
entered on the chart.
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26 Warwick Manufacturing Group Revision date: January 07
Figure 12. Customer complaint history.
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27 Warwick Manufacturing Group Revision date: January 07
Establishing Priorities This stage of the QFD study is in fact
optional, but is the area which allows the company to make major
improvements quickly. In some cases where the information mentioned
in the previous sections has been entered on the chart it will
point to an area of major customer dissatisfaction. That is to say
a customer requirement which is seen as being highly important by
the customer we as a company are the worst of our competitors. This
may also be backed up by a very large customer complaint history.
If this is the case, the QFD team may decide to begin a study of
the particular issue concerned before continuing with the QFD
study.
The diagram overleaf shows two items which could be seen as
priorities for the aircraft seat example.
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28 Warwick Manufacturing Group Revision date: January 07
Figure 13. Customer priorities.
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29 Warwick Manufacturing Group Revision date: January 07
Figure 14. Engineering characteristics.
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30 Warwick Manufacturing Group Revision date: January 07
Establish Engineering Characteristics The starting point for QFD
is positive statements of Customer Requirements expressed in the
customers own language. This data is then organised into logical
groups and your competitive position, as perceived by your
customers, is determined against these requirements.
The next step is to determine the Engineering Characteristics
which must be optimised to assure customer satisfaction. The
marketing domain tells us what to do, the engineering domain tells
us how to do it.
The Customer Requirements are listed down the left hand side of
the chart. The QFD team then lists, along the top, those
Engineering Characteristics that are likely to affect one or more
of the Customer Requirements.
Engineering Characteristics should describe the product in
measurable terms and should directly affect customer perceptions.
This translation of Customer Requirements into language meaningful
to a designer is a very important step in the QFD process and
deserves considerable study and development. If the step is
performed correctly the customers voice will be carried through. If
not, one of the major objectives of the study, the customers voice,
will have been lost.
Teams should avoid ambiguity in interpretation of the
Engineering Characteristics. They must avoid hasty decisions that a
Customer Requirement is satisfied by using current quality control
measurement practices. If you do what you have always done, you
will get what you have always got. This is a time for systematic,
creative and exhaustive analysis of each of the requirements, a
time for brainstorming.
This process need not be conducted by the QFD team alone.
Subgroups may be formed with members brought in from outside the
core team, but each subgroup should be led by a team member.
Brainstorm each secondary, and its associated tertiary
requirements, to generate Engineering Characteristics. As many
ideas as possible should be generated, both established and novel
approaches, any aspect of engineering that affects at least one of
the Customer Requirements. However, there is one overriding
requirement that must be rigidly enforced. Each Engineering
Characteristic must be measurable. If is not measurable, it cannot
be optimised and so cannot be used to assure customer
satisfaction.
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31 Warwick Manufacturing Group Revision date: January 07
From the study of the aircraft seat the following was
generated.
STEP 1 - Brainstorming
Secondary Requirement Tertiary Requirements
Comfortable Upright Arm rest folds right away Arm rest wide
enough Enough leg room Doesnt give you bum ache Doesnt hurt the
shoulders of tall person Lumbar support doesnt hurt back of short
person
Engineering Characteristics
Width of gap between seat backs Depth of gap between seat backs
Width of arm rest Thickness of seat back Profile of seat back
(front and back) Pan height Pan profile Lumps of adhesive left on
surface of structure Position of upholstery attachments Foam
thickness Foam hardness
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32 Warwick Manufacturing Group Revision date: January 07
STEP 2 - Grouping data
These ideas must now be grouped under three headings, and as a
check that all the Engineering Characteristics are measurable, the
units of measurement must be defined.
Human Requirements
Process Requirements
Engineering Characteristics
Units of Measurement
Wipe excess adhesive off seat structure during assembly.
Seat gap width
Seat gap depth
mm
mm
Train assembly staff to attach covers on the back and side
offset only.
Grind off any lumps of set adhesive after assembly.
Arm rest width
Seat back thickness
Seat back profile
Seat pan profile
Seat pan height
Foam thickness
Foam hardness
mm
mm
mm (x, y, z)
mm (x, y, z)
mm
mm
Vickers
STEP 3 - Entry onto QFD chart
Once the Engineering Characteristics are established, they must
be entered along the top of the QFD chart as shown below.
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33 Warwick Manufacturing Group Revision date: January 07
Figure 15. Engineering characteristics - aircraft seat
example.
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34 Warwick Manufacturing Group Revision date: January 07
Figure 16. Technical competitive comparisons.
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35 Warwick Manufacturing Group Revision date: January 07
Technical Competitive Comparisons The next step is to evaluate
how your company performs in comparison to its most serious
competitors.
If your company continually evaluates its products performance
competitively against other products in the market place, much of
the required data, along with the organisational structure
necessary to obtain it, will already exist.
If this is not the case, you will have to obtain the products
(buy or rent) or get access to them (how?), to conduct the
analysis. In many situations solution of this problem will require
some lateral thinking.
Basically, you have to get hold of your competitors products,
tear them apart and compare them to yours.
A few typical examples are:
Consumer product: use it then reverse engineer it. Computer
software: try it out, benchmark it against your software. A shop:
go and buy something there.
The Engineering Characteristics already identified must be
matched up and competitive rankings determined on those specific
points. In addition, you should always be on the look out for any
other areas in which your competition has the edge on you.
It is important that the QFD team work closely with the test
personnel who will conduct the competitive analysis. There will be
cases where an Engineering Characteristic cannot be competitively
evaluated by a standard company test. In these instances it will be
necessary for the team to help design a new test.
Competitive comparisons provide a company with the hard facts
about where its products stand technically in relation to its
competitors products. This knowledge is vitally important to the
QFD team during the analysis stage of the study.
It will rarely prove possible to easily evaluate all of the
Engineering Characteristics. Competitive comparisons should become
an on going process with team members striving to develop data for
every characteristic. In many cases this ideal situation will never
be achieved.
Aircraft Seat Study The method of classification will vary from
product to product, as will methods of testing. Below is shown an
extract from the Technical Competitive Comparison performed on
aircraft seats. You will have to develop your own methods but it is
strongly recommended that you lay out the data in a form similar to
that shown.
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36 Warwick Manufacturing Group Revision date: January 07
Engineering Characteristics
Com
pany
(A=U
s)
Measured Data
Ave
rage
va
lue
Val
ue
sele
cted
as
Val
ue
on
1-5
scal
e
Seat back thickness A
B
C
28 mm
36 mm
25 mm
29.6
30
3.2
2.5
3.6
Seat back profile A
B
C
Smooth, doubly curved
Flat
Smooth, singly curved
____
4
1
3
In this case of the seat back thickness the technical comparison
involved only a simple measurement. The average thickness of the
three seat backs was rounded up and taken as the normal value. The
1-5 value was then calculated by the following equation:
2.332830 =
i.e. the ratio of (the normal value) divided by (the measured
value), multiplied by (the mid value in the 1-5 scale).
In the above, the driving force is to minimise the thickness. In
a situation where the driving force is to maximise the value of the
Engineering Characteristic, the ratio must be inverted.
In the case of the seat back profile, the technical position
could not be evaluated by a simple measurement. It is valid to
include profile as an Engineering Characteristic since the profile
can be measured in terms of its coordinate geometry (x y z) and its
curvature at any particular point. The problem is that there are no
established rules for judging the comfort of a seat back from the
coordinate measurements.
In this instance the three different profiles were subjectively
evaluated by customers and their relative comforts judged. Based on
these judgments the values shown were selected by the team
members.
This is a typical example where further work is required - in
this case to determine the comfort parameters of a seat back
profile. This is an ideal situation in which to conduct a set of
Taguchi experiments.
This data must now be entered on to the QFD chart as shown on
the next page.
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37 Warwick Manufacturing Group Revision date: January 07
Figure 17. Technical competitive comparisons - aircraft seat
example.
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38 Warwick Manufacturing Group Revision date: January 07
Other Sources of Data As stated earlier, the method of
classification will vary from industry to industry. This is also
true of other sources of relevant information. One commonly used
source is that of the service history of the product. Data
concerning the number of service repairs performed on any
particular Engineering Characteristic (or groups of
characteristics) should be collected, as should the cost of the
repairs. In the case of computer software the data may take the
form of the number of fixes released and the areas they covered.
Think laterally about such sources of data. The one criterion is
that it should relate to the performance of one or more Engineering
Characteristics.
If such data is collected, it should be entered on to the chart
below the Technical Competitive Comparison and above the Technical
and Regulatory Requirements, as shown on the next page.
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39 Warwick Manufacturing Group Revision date: January 07
Figure 18. Other sources of technical data.
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40 Warwick Manufacturing Group Revision date: January 07
Figure 19. Establishing links.
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41 Warwick Manufacturing Group Revision date: January 07
Establishing Links This stage involves filling in the
Relationships Matrix in the main body of the chart and the
triangular Conflicts Matrix at the top of the chart. The idea is to
highlight relationships between Customer Requirements and
Engineering Characteristics, and conflict/supporting relationships
amongst the Engineering Characteristics. In addition to
highlighting the relationships their relative strengths must also
be judged and a range of symbols is used to represent this.
Relationships Matrix This matrix highlights the relationships
between the Customer Requirements and the Engineering
Characteristics. It must also be remembered to include the
Technical and Regulatory Requirements in the correlation.
The team members should seek consensus on these evaluations,
basing them on expert engineering experience, customer responses
and data from statistical studies and controlled experiments.
There will be varying degrees of the strength of the
relationships and so a set of symbols is used to identify the
significance.
The symbols used are:
~ Strong relationship { Medium relationship U Weak
relationship
As an example, an extract from the aircraft seat study is shown
on the next page.
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42 Warwick Manufacturing Group Revision date: January 07
Figure 20. Establishing links relationship matrix.
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43 Warwick Manufacturing Group Revision date: January 07
Looking at the first Customer Requirement, Arm rest folds right
away, you see that this is strongly related to width of arm rest,
arm rest recess depth and arm rest recess width.
In addition, the team felt that there was a weak relationship to
the height of back and a medium relationship with the back
thickness.
Every intersection between a Customer Requirement and an
Engineering Characteristic should be carefully considered. However,
it should be noted that in the example shown less than 20% of the
available space has actually been used. This is not unusual. In any
event, intersection symbols should certainly occupy less than 50%
of the available space.
Conflicts Matrix This is the triangular matrix at the top of the
chart. It is used to highlight relationships between the
Engineering Characteristics. As before, symbols are used to
indicate the strength of the relationship but in addition, they
also indicate whether it is a positive supporting relationship or a
negative conflicting relationship.
The symbols used are:
~ Strong positive relationship { Positive relationship
Supportive Negative relationship Strong negative relationship
Conflicting
On the next page is an extract from the aircraft seat study.
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44 Warwick Manufacturing Group Revision date: January 07
Width of armrest
Armrest recess depth
Armrest recess width
Height of back
Profile of back
Profile of pan
Back thickness
Pan height
Back hinge location
Loci of hinge
Clutch locking force
Clutch resistance (open)
Fabric tear resistance
Fabric wear resistance
Washable fabric
Stain resistant fabric
Liquid resistant fabric
Fatigue performance
Structural strength
Structural stiffness
Material FST Performance
Foam stiffness
Foam thickness
Mountings interchangeable
Number of fasteners
Location of fasteners
Arm
rest
Bac
kFa
bric
Stru
ctur
e
All
Foam
Mou
ntin
gs
Item
Numb
er
12
34
56
78
910
1112
1314
1516
1718
1920
2122
2324
2526
STR
ON
G P
OSI
TIV
E R
ELA
TIO
NSH
IP
POSI
TIV
E R
ELA
TIO
NSH
IP
NE
GA
TIV
E R
ELA
TIO
NSH
IP
STR
ON
G N
EG
AT
IVE
RE
LAT
ION
SHIP
Figure 21. Establishing links - correlation matrix
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45 Warwick Manufacturing Group Revision date: January 07
Consider item 5 Profile of back.
The matrix is completed by moving up to the beginning of the
angled column, then moving along this column to the top right.
Again, every intersection should be carefully considered.
The first intersection is with the seat back thickness. This has
been highlighted as a strong negative relationship since they are
in conflict. The aim is to have as thin a back as possible, but
this would result in a flat back, not a comfortable moulded
profile. Moving further along a positive relationship has been
shown against Fatigue performance. This is because a curved profile
will increase the rigidity of the back and improve its structural
performance. Similar arguments have been used to assign symbols to
the rest of the boxes where necessary.
Negative symbols show where a tradeoff situation exists that
must be resolved. These will be considered in the next stage when
the target values for the Engineering Characteristics are
established.
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46 Warwick Manufacturing Group Revision date: January 07
Figure 22. Technical targets and ratings.
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47 Warwick Manufacturing Group Revision date: January 07
Establishing technical targets and ratings Once the
relationships (correlations and conflicts) have been established,
the next stage is to determine target values for the engineering
characteristics, a rating of the difficulty of achieving that
target and an importance rating for the engineering
characteristics.
Engineering Targets These engineering targets are very different
from the normal design specifications with which most people are
familiar. Design specifications reflect the engineers judgment and
knowledge of prior problems and manufacturing capabilities.
Engineering targets on the other hand only reflect what is needed
to assure customer satisfaction. They bear no relation to what
currently can be achieved.
In choosing target values you should consider several things.
Firstly, the ratings and absolute values determined in the
technical competitive comparison. Secondly, the importance ratings
of the customer requirements you are trying to satisfy along with
the associated data from the customer competitive comparisons.
Thirdly, you should consider any relationships, positive and
negative, highlighted in the conflicts matrix.
Consider the 6th engineering characteristic from the aircraft
seat study:
Seat back thickness
The technical competitive comparison gave the following:
Company A(us) 28 mm
B 36 mm
C 25 mm
Looking through the customer requirements that are affected by
the back thickness, we see there is a strong relationship with
Enough leg room. This is rated highly with an importance of 8. The
customers see us as performing equal best, but there is room for
improvement.
Further down we see a strong relationship with Fit more
passengers in. This is rated with an importance of 5 and the
customers see us as being equal worse.
Next look at the conflicts and bear in mind that we must not
compromise the strength and stiffness of the back and that we must
still be able to accommodate the hinge pivot in the back.
Balancing all this, it was decided to match the best performer,
and aim to reduce the back thickness to 25 mm. The airline could
then have the choice of giving the passengers extra leg room or of
shunting the seats closer together to get an extra row in.
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48 Warwick Manufacturing Group Revision date: January 07
A similar process was used to determine target values for all
the engineering characteristics. When we come to the analysis stage
and study the completed chart, a few of the values may have to be
slightly modified. The number requiring modification will depend
upon how well this stage was performed.
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49 Warwick Manufacturing Group Revision date: January 07
Figure 23. Establishing engineering targets.
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50 Warwick Manufacturing Group Revision date: January 07
Degree of Technical Difficulty A key factor that influences the
analysis stage is the level of technical difficulty expected to be
encountered in achieving the engineering characteristics target
values.Since each study represents a unique situation, the method
of determining the level of difficulty will have to be adapted to
suit each QFD study.
The areas to be considered may include design, purchasing,
manufacturing, packaging, suppliers etc. Each QFD team will have to
develop its own approach and decide on the degree of technical
difficulty.
In the aircraft seat study a scale of 1-5 was used with 5 being
most difficult. All the functions affected by the proposed design
changes were included in the determination of the value. In the
case of the seat back thickness, only the design department was
affected by the proposed reduction to 25 mm. However, it was felt
that a major structural redesign would be required to achieve the
desired thickness and so it was rated with a value of 5.
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51 Warwick Manufacturing Group Revision date: January 07
DE
GR
EE
OF
TE
CH
NIC
AL
DIF
FIC
ULT
Y 54321=A =B =C
Wor
se
Bes
t
TE
CH
NIC
AL
CO
MP
ETIT
IVE
CO
MPA
RIS
ON
S
TE
CH
NIC
AL
TA
RG
ETS
50 mm
80 mm
55 mm
580 mm
T.B.I.
T.B.I.
T.B.I.
25 mm
450 mm
x=150, y=50
100 N
5 N
3 mm Test
1x10 strokes
6
100 washers
Test 013
1 gm/hr
1x10 cycles
6
7000 N Test
70 mm at 7000 N
5 min +
20 MN/m
2
25 mm
Interchange
4
Over rails
12
42
44
53
35
44
43
24
44
44
42
21
31
Figure 24. Establishing degree of technical difficulty.
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52 Warwick Manufacturing Group Revision date: January 07
Engineering Characteristic Importance Rating These ratings are a
combination of the customer importance rating and the strength of
the relationships between the customer requirements and the
engineering characteristics.
Values are assigned to the correlation symbols. The recommended
values are:
Strong relationship ~ = 9 Medium relationship { = 3 Weak
relationship U = 1 The ratings are calculated by summing down each
column the product of the customer importance rating and the value
assigned to the correlation symbol.
As an example consider the first column in the aircraft seat
example, the Width of the armrest. The absolute importance rating
of 114 is calculated from:
(5 x 9) + (5 x 9) + (9 x 1) + (5 x 3) = 114
The relative value is simply the absolute value expressed as a
percentage of the total.
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53 Warwick Manufacturing Group Revision date: January 07
MARKETQUALITYREQUIREMENTS
ENGINEERINGCHARACTERISTICS
PRIM
ARY
SECO
NDAR
Y
TERTIARY
Arm rest folds right away
Arm rest wide enough
Enough leg room
Doesn't give you bum ache
Doesn't hurt shoulders oftaller person
Lumbar support doesn'thurt shorter person
Doesn't hit person behindwhen you recline
Back can be adjusted to anyposition and doesn't slip
Com
fort
able
Upr
ight
Com
fort
able
Rec
linedPa
ssen
gers
Fee
l Com
fort
able
5588
7
7
7
8
DEGREE OF IMPORTANCE
Wid
th o
f arm
rest
Arm
rest
rec
ess
dept
h
Arm
rest
rec
ess
wid
th
Hei
ght o
f bac
k
Pro
file
of b
ack
Pro
file
of p
an
Bac
k th
ickn
ess
Pan
heig
ht
Bac
k hi
nge
loca
tion
Loci
of h
inge
Clu
tch
lock
ing
forc
e
Clu
tch
resis
tanc
e (o
pen)
Fabr
ic te
ar r
esis
tanc
e
Fabr
ic w
ear
resi
stan
ce
Was
habl
e fa
bric
Stai
n re
sist
ant f
abri
c
Liqu
id r
esist
ant f
abri
c
Fati
gue
perf
orm
ance
Stru
ctur
al st
reng
th
Stru
ctur
al st
iffne
ss
Mat
eria
l FST
Per
form
ance
Foam
stiff
ness
Foam
thic
knes
s
Mou
ntin
gs in
terc
hang
eabl
e
Num
ber
of fa
sten
ers
Loca
tion
of fa
sten
ers
Armrest Back Fabric Structure All
Foam Mountings
Item Number
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
25 26
Doesn't soak up spilt drink
Easy to clean
Fabric stain resistant
Durable
Light weight
Easy to move around
Fit more passengers in
Low
Ser
vice
Cos
tsL
ow O
pera
ting
Cos
ts
Cos
t
5666945
Tec
hnic
al a
nd
Reg
ula
tory
Req
uir
emen
ts
FST 1000
16 G LOAD CASE
MAX ALLOWABLE DEFLECTION
INTERFACE TO FLOOR RAILS
ENG. CHAR. IMPORTANCE RATINGS
ABSOLUTE
RELATIVE
114
5
54
2
54
2
182
8
290
12
24
1
204
9
105
4
87
4
63
3
81
3
72
3
54
2
54
2
54
2
108
5
117
5
81
3
135
6
81
3
27
1
120
5
123
5
36
2
63
3
36
2
Figure 25. Engineering characteristics importance ratings.
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54 Warwick Manufacturing Group Revision date: January 07
Figure 26. Analysing the QFD chart.
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55 Warwick Manufacturing Group Revision date: January 07
Analysing The QFD Chart As the QFD chart nears completion, the
data that has been accumulated and organised must be analysed and,
where necessary, target values finalised. The analysis of the chart
will identify several key areas:
Areas in which you hold the lead but must maintain your
position. Areas where you can gain a competitive advantage. Areas
where you lag behind and must catch up with your competitors.
There are no set procedures for analysing the chart. The team
must work together allowing free and open discussion. They must
systematically examine each customer requirement and all the
associated data. A few specific areas which must be looked at will
be described and a fuller picture will be given by the worked
example.
Initially check each row and column for strong relationships. If
none are shown it deserves detailed attention. In the case of a
column it shows that an Engineering Characteristic has been
introduced that is not needed. It is not uncommon to find
Engineering Characteristics that are historic or represent the
voice of the engineer and have no real relationship with a customer
requirement.
In the case of a row it means that a Customer Requirement may
not have been adequately satisfied. If this occurs, check your
correlations to make sure that you have not missed something. If
necessary, run a brain storming session to generate Engineering
Characteristics to satisfy the customer requirement. This situation
is particularly serious if it concerns a technical or regulatory
requirement. These must be satisfied otherwise you may not be able
to make the product or, if you do, it may not meet legal
requirements.
A QFD study is all about finding out what your customers want
and assuring that features are built into the end product to ensure
that these wants are satisfied. This should be borne in mind while
analysing the chart. Start with the customer requirements and
systematically examine your competitive position and your
capability for improving. Work through the Customer Requirements in
the order of their Importance Rating - the most important
first.
In the aircraft seat study the highest ranked customer
requirement is that of Light Weight. Looking at the competitive
comparison we see that we are rated the best but Company C is in a
fairly close second place. Of the Engineering Characteristics that
affect the weight, two are strongly related and three have a medium
correlation. The degree of technical difficulty is 4 for the two
strong correlations and 2, 4, 4 for the others. There are no areas
which can be easily tackled to reduce weight, but this is seen as
the most important aspect of the seat. We have the lightest seat in
the market and this position must be maintained.
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56 Warwick Manufacturing Group Revision date: January 07
Looking at Doesnt give you bum ache as the next customer
requirement, we see that this has an importance of 8 and all the
seats are competitively ranked equal with a rating of 3. There is
clearly an opportunity here to gain a competitive advantage if the
technical problems can be overcome. The strong relationships are
with pan profile, foam hardness and foam thickness.
The foam can easily be changed (technical difficulty = 2) but
the pan profile has a difficulty of 4 associated with it. If the
pan profile can be improved we can take the lead.
Further through the analysis we see that we are rated as the
worst performer for short person lumbar comfort. This has an
importance rating of 7. The factor which strongly affects this is
the back profile, along with foam hardness and foam thickness of
secondary importance. This is clearly an area in which we must
improve. The technical difficulty of changing the foam is only 2.
This maybe the route forward to tackle the problem in the short
term. Longer term the back profile must be modified to make it more
comfortable.
As stated earlier, the target values are the levels of
performance required for each engineering characteristic to fulfill
customer expectations. They must not be based on any level of
capability. If during the analysis stage it becomes apparent that
the above has not been honoured, then the target value must be
modified.
-
Q U A L I T Y F U N C T I O N D E P L O Y M E N T
57 Warwick Manufacturing Group Revision date: January 07
RELATIONSHIPS
9 STRONG
3 MEDIUM
1 WEAK
CORRELATION
STRONG +
POSITIVE
NEGATIVE
STRONG -
CUSTOMERRATING
1 2 3 4 5
WO
RST
BEST
SER
VIC
E C
OM
PLA
INT
S
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
MAX MIN TARGET
ENGINEERINGCHARACTERISTICS
IMPORTANCE
DEGREE OF TECHNICAL DIFFICULTY
TECHNICALTARGETS
TECHNICALCOMPETITIVECOMPARISONS
WORSE
BETTER4321
5
Tech
nica
l an
dR
egul
ator
y R
equi
rem
ents
Eng Char.Importance Ratings
ABSOLUTE
RELATIVE
MARKETQUALITYREQUIREMENTS
21 22 23 24 25 26 27 28 29 30
= B= A
= C
50 m
m
80 m
m
55 m
m
580
mm
T.B.
I.
T.B.
I.
25 m
m
450
mm
x=15
0, y
=50
T.B.
I.
100
N
5 N
3 m
m T
est
1x10
6 st
roke
s
1x10
6 cy
cles
100
wash
ers
Test
013
1 gm
/hr
7000
N T
est
70 m
m a
t 700
0 N
5 m
in +
20 M
N/m
2
25 m
m
Inte
rcha
nge
4 Ove
r ra
ils1 2 4 2 4 4 5 3 3 5 4 4 4 3 2 4 4 4 4 4 4 2 2 1 3 1
Arm rest fold right away
Arm rest wide enough
Enough leg room
Doesn't give you bum ache
Doesn't hurt the shoulders of a taller person
Lumbar support doesn't hurt shorter person
Doesn't hit person behind when you recline
Back can be adjusted to any position and doesn't slip
Doesn't soak up spilt drink
Easy to clean
Fabric stain resistant
Durable
Light weight
Easy to move around
Com
fort
able
Upr
ight
Com
fort
able
Rec
lined
Low
Ser
vice
Cos
tsLo
w O
pera
ting
Cos
ts
Pass
enge
rs F
eel C
omfo
rtab
leC
ost
Wid
th o
f arm
rest
Arm
rest
rece
ss d
epth
Arm
rest
rece
ss w
idth
Hei
ght o
f ba
ck
Prof
ile o
f bac
kPr
ofile
of p
anB
ack
thic
knes
sPa
n he
ight
Bac
k hi
nge
loca
tion
Loci
of h
inge
Clu
tch
lock
ing
forc
e
Clu
tch
resi
stan
ce (o
pen
)Fa
bric
tear
resi
stan
ce
Fabr
ic w
ear
resi
stan
ceW
asha
ble
fabr
icSt
ain
resi
stan
t fab
ric
Liqu
id r
esis
tant
fabr
ic
Fati
gue
perf
orm
ance
Stru
ctur
al s
tren
gth
Stru
ctur
al s
tiffn
ess
Mat
eria
l FST
per
form
ance
Foam
stif
fnes
sFo
am th
ickn
ess
Mou
ntin
gs in
terc
hang
eabl
e
Num
ber
of fa
sten
ers
Loca
tion
of fa
sten
ers
Armrest Back Fabric Structure All Foam Mountings
FST 1000
16 G LOAD CASE
MAX ALLOWABLE DEFLECTIONINTERFACE TO FLOOR RAILS
114 54 54 182 290 24204 105 87 63 81 72 54 54 54 108 117 81 135
81 27120 123 36 63 36
5 2 2 8 12 1 9 4 4 3 3 3 2 2 2 5 5 3 6 3 1 5 5 2 3 2
5
5
8
8
7
7
7
8
5
6
6
6
9
4
5
5
12
3
3
5
2
8
Item Number
Fit more passengers in
ANALYSING THE CHART
CHECK ROWS AND COLUMNS FOR STRONG RELATIONSHIPS
Figure 27. Analysing the chart for strong relationships.
-
Q U A L I T Y F U N C T I O N D E P L O Y M E N T
58 Warwick Manufacturing Group Revision date: January 07
RELATIONSHIPS
9 STRONG
3 MEDIUM
1 WEAK
CORRELATION
STRONG +
POSITIVE
NEGATIVE
STRONG -
CUSTOMERRATING
1 2 3 4 5
WO
RST
BEST
SER
VIC
E C
OM
PLA
INT
S
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
MAX MIN TARGET
ENGINEERINGCHARACTERISTICS
IMPORTANCE
DEGREE OF TECHNICAL DIFFICULTY
TECHNICALTARGETS
TECHNICALCOMPETITIVECOMPARISONS
WORSE
BETTER4321
5
Tech
nica
l and
Reg
ulat
ory
Req
uire
men
ts
Eng Char.Importance Ratings
ABSOLUTE
RELATIVE
MARKETQUALITYREQUIREMENTS
21 22 23 24 25 26 27 28 29 30
= B= A
= C
50 m
m
80 m
m
55 m
m
580
mm
T.B.
I.
T.B.
I.
25 m
m
450
mm
x=15
0, y
=50
T.B.
I.
100
N
5 N
3 m
m T
est
1x10
6 str
okes
1x10
6 cy
cles
100
wash
ers
Test
013
1 gm
/hr
7000
N T
est
70 m
m a
t 700
0 N
5 m
in +
20 M
N/m
2
25 m
m
Inte
rcha
nge
4 Ove
r ra
ils
1 2 4 2 4 4 5 3 3 5 4 4 4 3 2 4 4 4 4 4 4 2 2 1 3 1
Arm rest fold right away
Arm rest wide enough
Enough leg room
Doesn't give you bum ache
Doesn't hurt the shoulders of a taller person
Lumbar support doesn't hurt shorter person
Doesn't hit person behind when you recline
Back can be adjusted to any position and doesn't slip
Doesn't soak up spilt drink
Easy to clean
Fabric stain resistant
Durable
Light weight
Easy to move around
Com
fort
able
Upr
ight
Com
fort
able
Rec
lined
Low
Ser
vice
Cos
tsLo
w O
pera
ting
Cos
ts
Pass
enge
rs F
eel C
omfo
rtab
leC
ost
Wid
th o
f arm
rest
Arm
rest
rece
ss d
epth
Arm
rest
rece
ss w
idth
Hei
ght o
f ba
ck
Prof
ile o
f bac
kPr
ofile
of p
anB
ack
thic
knes
sPa
n he
ight
Bac
k hi
nge
loca
tion
Loci
of h
inge
Clu
tch
lock
ing
forc
e
Clu
tch
resi
stan
ce (o
pen
)Fa
bric
tear
resi
stan
ce
Fabr
ic w
ear
resi
stan
ceW
asha
ble
fabr
icSt
ain
resi
stan
t fab
ric
Liqu
id r
esis
tan
t fab
ric
Fati
gue
perf
orm
ance
Stru
ctur
al s
tren
gth
Stru
ctur
al s
tiffn
ess
Mat
eria
l FST
per
form
ance
Foam
stif
fnes
sFo
am th
ickn
ess
Mou
ntin
gs in
terc
hang
eabl
e
Num
ber
of fa
sten
ers
Loca
tion
of fa
sten
ers
Armrest Back Fabric Structure All Foam Mountings
FST 1000
16 G LOAD CASE
MAX ALLOWABLE DEFLECTIONINTERFACE TO FLOOR RAILS
114 54 54 182 290 24204 105 87 63 81 72 54 54 54 108 117 81135
81 27 120 123 36 63 36
5 2 2 8 12 1 9 4 4 3 3 3 2 2 2 5 5 3 6 3 1 5 5 2 3 2
5
5
8
8
7
7
7
8
5
6
6
6
9
4
5
5
12
3
3
5
2
8
Item Number
Fit more passengers in
ANALYSING THE CHART
AREAS IN WHICH WE HOLD THE LEAD AND MUST MAINTAIN OUR
POSITION
Light weight 9
18 19 20 21
1x10
6 cy
cles
7000
N T
est
70 m
m a
t 700
0 N
5 m
in +
4 4 4 4
Fati
gue
perf
orm
ance
Stru
ctur
al s
tren
gth
Stru
ctur
al s
tiffn
ess
Mat
eria
l FST
per
form
ance
81135 81 27
3 6 3 1
4
580
mm
2
Hei
ght o
f ba
ck
182
8
Figure 28. Analysing the chart for whene we hold the lead.
-
Q U A L I T Y F U N C T I O N D E P L O Y M E N T
59 Warwick Manufacturing Group Revision date: January 07
RELATIONSHIPS
9 STRONG
3 MEDIUM
1 WEAK
CORRELATION
STRONG +
POSITIVE
NEGATIVE
STRONG -
CUSTOMERRATING
1 2 3 4 5
WO
RST
BEST
SER
VIC
E C
OM
PLA
INT
S
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
MAX MIN TARGET
ENGINEERINGCHARACTERISTICS
IMPORTANCE
DEGREE OF TECHNICAL DIFFICULTY
TECHNICALTARGETS
TECHNICALCOMPETITIVECOMPARISONS
WORSE
BETTER4321
5
Tech
nica
l an
dR
egul
ator
y R
equi
rem
ents
Eng Char.Importance Ratings
ABSOLUTE
RELATIVE
MARKETQUALITYREQUIREMENTS
21 22 23 24 25 26 27 28 29 30
= B= A
= C
50 m
m
80 m
m
55 m
m
580
mm
T.B.
I.
T.B.
I.
25 m
m
450
mm
x=15
0, y
=50
T.B.
I.
100
N
5 N
3 m
m T
est
1x10
6 st
roke
s
1x10
6 cy
cles
100
wash
ers
Test
013
1 gm
/hr
7000
N T
est
70 m
m a
t 700
0 N
5 m
in +
20 M
N/m
2
25 m
m
Inte
rcha
nge
4 Ove
r ra
ils1 2 4 2 4 4 5 3 3 5 4 4 4 3 2 4 4 4 4 4 4 2 2 1 3 1
Arm rest fold right away
Arm rest wide enough
Enough leg room
Doesn't give you bum ache
Doesn't hurt the shoulders of a taller person
Lumbar support doesn't hurt shorter person
Doesn't hit person behind when you recline
Back can be adjusted to any position and doesn't slip
Doesn't soak up spilt drink
Easy to clean
Fabric stain resistant
Durable
Light weight
Easy to move around
Com
fort
able
Upr
ight
Com
fort
able
Rec
lined
Low
Ser
vice
Cos
tsLo
w O
pera
ting
Cos
ts
Pass
enge
rs F
eel C
omfo
rtab
leC
ost
Wid
th o
f arm
rest
Arm
rest
rece
ss d
epth
Arm
rest
rece
ss w
idth
Hei
ght o
f ba
ck
Prof
ile o
f bac
kPr
ofile
of p
anB
ack
thic
knes
sPa
n he
ight
Bac
k hi
nge
loca
tion
Loci
of h
inge
Clu
tch
lock
ing
forc
e
Clu
tch
resi
stan
ce (o
pen
)Fa
bric
tear
resi
stan
ce
Fabr
ic w
ear
resi
stan
ceW
asha
ble
fabr
icSt
ain
resi
stan
t fab
ric
Liqu
id r
esis
tant
fabr
ic
Fati
gue
perf
orm
ance
Stru
ctur
al s
tren
gth
Stru
ctur
al s
tiffn
ess
Mat
eria
l FST
per
form
ance
Foam
stif
fnes
sFo
am th
ickn
ess
Mou
ntin
gs in
terc
hang
eabl
e
Num
ber
of fa
sten
ers
Loca
tion
of fa
sten
ers
Armrest Back Fabric Structure All Foam Mountings
FST 1000
16 G LOAD CASE
MAX ALLOWABLE DEFLECTIONINTERFACE TO FLOOR RAILS
114 54 54 182 290 24204 105 87 63 81 72 54 54 54 108 117 81135
81 27120123 36 63 36
5 2 2 8 12 1 9 4 4 3 3 3 2 2 2 5 5 3 6 3 1 5 5 2 3 2
5
5
8
8
7
7
7
8
5
6
6
6
9
4
5
5
12
3
3
5
2
8
Item Number
Fit more passengers in
ANALYSING THE CHART
AREAS WHERE WE CAN GAIN A COMPETITIVE ADVANTAGE
Doesn't give you bum ache 8 12
22 23
20 M
N/m
2
25 m
m
2 2
Foam
stif
fnes
sFo
am th
ickn
ess
120123
5 5
5T.
B.I.
4
Prof
ile o
f bac
k
290
12
8
450
mm
3
Pan
heig
ht
105
4
Figure 29. Analysing the chart for where we can gain competitive
advantage.
-
Q U A L I T Y F U N C T I O N D E P L O Y M E N T
60 Warwick Manufacturing Group Revision date: January 07
RELATIONSHIPS
9 STRONG
3 MEDIUM
1 WEAK
CORRELATION
STRONG +
POSITIVE
NEGATIVE
STRONG -
CUSTOMERRATING
1 2 3 4 5
WO
RST
BEST
SER
VIC
E C
OM
PLA
INT
S
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
MAX MIN TARGET
ENGINEERINGCHARACTERISTICS
IMPORTANCE
DEGREE OF TECHNICAL DIFFICULTY
TECHNICALTARGETS
TECHNICALCOMPETITIVECOMPARISONS
WORSE
BETTER4321
5
Tech
nica
l an
dR
egul
ator
y R
equi
rem
ents
Eng Char.Importance Ratings
ABSOLUTE
RELATIVE
MARKETQUALITYREQUIREMENTS
21 22 23 24 25 26 27 28 29 30
= B= A
= C
50 m
m
80 m
m
55 m
m
580
mm
T.B.
I.
T.B.
I.
25 m
m
450
mm
x=15
0, y
=50
T.B.
I.
100
N
5 N
3 m
m T
est
1x10
6 st
roke
s
1x10
6 cy
cles
100
wash
ers
Test
013
1 gm
/hr
7000
N T
est
70 m
m a
t 700
0 N
5 m
in +
20 M
N/m
2
25 m
m
Inte
rcha
nge
4 Ove
r ra
ils
1 2 4 2 4 4 5 3 3 5 4 4 4 3 2 4 4 4 4 4 4 2 2 1 3 1
Arm rest fold right away
Arm rest wide enough
Enough leg room
Doesn't give you bum ache
Doesn't hurt the shoulders of a taller person
Lumbar support doesn't hurt shorter person
Doesn't hit person behind when you recline
Back can be adjusted to any position and doesn't slip
Doesn't soak up spilt drink
Easy to clean
Fabric stain resistant
Durable
Light weight
Easy to move around
Com
fort
able
Upr
ight
Com
fort
able
Rec
lined
Low
Ser
vice
Cos
tsLo
w O
pera
ting
Cos
ts
Pass
enge
rs F
eel C
omfo
rtab
leC
ost
Wid
th o
f arm
rest
Arm
rest
rece
ss d
epth
Arm
rest
rece
ss w
idth
Hei
ght o
f ba
ck
Prof
ile o
f bac
kPr
ofile
of p
anB
ack
thic
knes
sPa
n he
ight
Bac
k hi
nge
loca
tion
Loci
of h
inge
Clu
tch
lock
ing
forc
e
Clu
tch
resi
stan
ce (o
pen
)Fa
bric
tear
resi
stan
ce
Fabr
ic w
ear
resi
stan
ceW
asha
ble
fabr
icSt
ain
resi
stan
t fab
ric
Liqu
id r
esis
tant
fabr
ic
Fati
gue
perf
orm
ance
Stru
ctur
al s
tren
gth
Stru
ctur
al s
tiffn
ess
Mat
eria
l FST
per
form
ance
Foam
stif
fnes
sFo
am th
ickn
ess
Mou
ntin
gs in
terc
hang
eabl
e
Num
ber
of fa
sten
ers
Loca
tion
of fa
sten
ers
Armrest Back Fabric Structure All Foam Mountings
FST 1000
16 G LOAD CASE
MAX ALLOWABLE DEFLECTIONINTERFACE TO FLOOR RAILS
114 54 54 182 290 24204 105 87 63 81 72 54 54 54 108 117 81 135
81 27 120 123 36 63 36
5 2 2 8 12 1 9 4 4 3 3 3 2 2 2 5 5 3 6 3 1 5 5 2 3 2
5
5
8
8
7
7
7
8
5
6
6
6
9
4
5
5
12
3
3
5
2
8
Item Number
Fit more passengers in
ANALYSING THE CHART
AREAS WHERE WE LAG BEHIND AND MUST IMPROVE
Lumbar support doesn't hurt shorter person 7 3
22 23
20 M
N/m
2
25 m
m
2 2
Foam
stif
fnes
sFo
am th
ickn
ess
120 123
5 5
5
T.B.
I.
4
Prof
ile o
f bac
k
290
12
Figure 30. Analysing the chart for where we lag and must
improve.
-
Q U A L I T Y F U N C T I O N D E P L O Y M E N T
61 Warwick Manufacturing Group Revision date: January 07
Next Steps The first level QFD study has now been completed. The
early stages were concerned with finding out what your customers
actually want in the product. We then moved on to developing
engineering characteristics that could be used to assure customer
satisfactio